Various types of artificial fuels and firelogs have been developed, most of which are formed of particulate flammable materials which are compressed into a predetermined shape. The particulate materials are combined with various wax binders or other resins for maintaining the desired shape of the final fuel body. These bodies also may contain various types of chemicals therein to enhance burning or to produce a colored flame.
Certain of these artificial fuels and in particular, the elongated fuel body referred to as a firelog, are formed of compressed sawdust, coal particles or other flammable material. Examples of prior art artificial firelogs are shown in U.S. Pat. Nos. 225,244, 1,050,535, 2,789,890, 3,637,355, 3,726,651, 3,947,255, 4,040,796, 4,147,518, 4,046,518, and 4,243,394.
These firelogs are formed usually by a continuous extrusion process wherein the particulate flammable material and the appropriate binder and other materials are compressed within an extrusion bore, and then are cut into predetermined lengths, and subsequently placed in a protective outer wrapper. Examples of such prior art extrusion processes are shown in several of the above referenced patents.
These firelogs are generally used by residential homeowners in a home fireplace to provide heat, and to provide an attractive fire closely simulating that of a natural wood fire. It is a common object of most artificial firelogs to provide some type of means for rapidly igniting the firelog, preferably when a match is applied to the outer wrapper, eliminating the need of any starting fuels which could be a safety hazard. It is also desirable that the log burns uniformally instead of at one or both ends only thereof, after being ignited by a starting match.
U.S. Pat. No. 4,040,796 in an attempt to provide uniform lighting and quick ignition of the firelog, forms a groove extending throughout the longitudinal length of the log which is filled with a quick ignition material. However, this construction, although providing a satisfactory quick-starting log, increases the cost of the log by the required addition of the quick ignition fuel-filled notch. Other prior art firelogs include quick ignition chemicals in the log itself. Other prior art firelogs attempt to increase the burning by forming a plurality of ridges and grooves to increase the surface area of the log such as shown in U.S. Pat. No. 3,726,651.
Another problem in the manufacturer of artificial firelogs is to control the weight of the flammable body, so as to meet the weight specifications thereof that is noted on the exterior of the wrapper, without excessively exceeding this required weight which results in increased usage of material, thereby increasing the cost of the firelog.